The deployment of expandable structures, sometimes generically called “balloons,” into cancellous bone is known. For example, U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose apparatus and methods using expandable structures to compact cancellous bone for the fixation of fractures or other osteoporotic and non-osteoporotic conditions of human and animal bones.
In these and other clinical indications, it is desirable to use tissue insertion and deployment tools that are small, so that access to the targeted tissue site can be achieved using minimally invasive procedures. Still, it is also desirable to deploy structures that, in use within the targeted tissue site, are capable of assuming enlarged, durable shapes, so that cortical bone can be displaced in a desired manner and/or large cavities can be created in cancellous bone without over-expansion, puncture, and/or abrasion of the structure.
There is a need to meet the demand for small insertion tools without conflicting with the objective to deploy large expandable structures.